This is what audio editors (Sound Forge, Cool Edit etc) are for - cutting'n'pasting of sounds. You could do this in Windows Sound Recorder even, if you have the disk space and the patience to splice together 120 samples.

Alternatively, you could simply press "record" in your Audio Application Of Choice (Windows Sound Recorder upwards), run your program, and leave it going for 60 minutes. Save As a .wav, burn with your CD Burner App. of choice and voila. Even without the diskspace, as all you have is a single beep, you could probably knock down the sample quality without missing too much.

A less tedious way would be to record / construct a (say) 5 minute chunk, then burn it as 12 duplicate tracks with no inter-track gap.